Using a tiny organ of our inner ear (otolith), we sense gravity and learn to take it into account from infancy when walking, running, or jumping. How much more difficult it is for astronauts when they have to cope with zero-gravity conditions in spaceflight!

Yes, gravity contributes to making life on earth normal for us.

[Picture on page 18]

From infancy a tiny organ in the ear helps us take gravity into account and keep our balance